Steroid therapy for polymyalgia rheumatica should make the patient feel better within days rather than weeks.
- British Society for Rheumatology (BSR) and British Health Professionals in Rheumatology (BHPR) guidelines recommends initiation of low dose steroid therapy with gradually tailored tapering in straight forward PMR
- it should be noted that in the absence of giant cell arteritis, urgent steroid therapy is not indicated before the clinical evaluation is complete.
- the suggested regimen is
- daily prednisolone 15 mg for 3 weeks
- then 12.5 mg for 3 weeks
- then 10 mg for 4–6 weeks
- then reduction by 1 mg every 4–8 weeks or alternate day reductions (e.g. 10/7.5 mg alternate days, etc.)
- this reccomendation should be flexible and tailored to the individual as there is heterogeneity in disease course
- adjustments of the steroid dose may be necessary according to the disease severity, comorbidity, side effects and patient wishes
- some patients may benefit from a more gradual steroid taper (1)
- IM methylprednisolone (i.m. depomedrone) may be used in milder cases and may reduce the risk of steroid-related complications
- initial dose is 120 mg every3–4 weeks, reducing by 20 mg every 2–3 months
- usually 1–2 years of treatment is needed
- treatment beyond 2 years should prompt the consideration of an alternative diagnosis and specialist referral (1)
- ESR and CRP normalise within one to two weeks and absence of prompt clinical and laboratory response should make one reconsider the diagnosis.
Note that as patients are weaned off corticosteroid therapy, some may require a small dose of NSAIDs at this stage to reduce muscle pain (2).
Use of bone protection when initiating steroids for PMR to prevent the complications of osteoporosis should be considered:
- individuals with high fracture risk, e.g. aged ≥65 years or prior fragility fracture
- bisphosphonate with calcium and vitamin D supplementaions
- DEXA not required
- other individuals
- calcium and vitamin D supplementation when starting steroid therapy
- DEXA recommended
- a bone-sparing agent may be indicated if T-score is -1.5 or lower.
- individuals requiring higher initial steroid dose
- bisphosphonate with calcium and vitamin D supplementation (because higher cumulative steroid dose is likely)(1)
Note also that, in addition to the risk of osteoporosis, corticosteroid therapy may cause gastric irritation and gastro-protection may be required (2).
Notes:
- the response to the initial glucocorticoid treatment could be viewed as an (admittedly imperfect) diagnostic test for PMR
- this 'test' is most specific for PMR as patients feel completely better ('magic' or 'miracle' effects) after 3 days of 15 mg prednisolone
- sensitivity of the 'trial of steroids' is probably improved, at the cost of some loss in specificity, if patients are allowed longer (1-2 weeks) to achieve a 70% reduction in symptom scores, or if they are given higher doses (e.g. 20-25 mg prednisolone)
- do not miss giant cell arteritis (3)
- estimated that 5-10% of patients with PMR are also diagnosed with giant cell arteritis (GCA); in some cases the GCA only appears later
- untreated GCA can result in permanent visual loss or stroke, and as such is a 'must not miss' diagnosis
- clinicians must informl patients with PMR to look out for headache, scalp tenderness, jaw pain/claudication and visual disturbance. GCA symptoms may need high glucocorticoid doses (usually at least 30-40 mg/day prednisolone) so the risk of steroid-associated side-effects is high. Patients suspected as having GCA should be urgently referred to local specialist services (usually rheumatology or ophthalmology, but this is dependent on local care pathways)
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